Electric arc welders of the GMAW type are often powered by a high speed switching power supply or power source with a controller for controlling the current waveform of the welding process. The Lincoln Electric Company of Cleveland, Ohio has pioneered the concept of an electric arc welder with a wave shaper to control the shape of the current waveform during each cycle by the use of high frequency current pulses, the magnitude of each pulse being controlled by a pulse width modulator. In such welders, the wave shape of the current is accurately controlled to perform such diverse welding processes as pulse welding, constant voltage welding, spray welding, pulse welding, short-arc CV welding and STT welding. In such processes, the wave shape for each weld cycle is controlled by the pulse width modulator to produce a series of welding cycles that perform a designated process. Such arc welders are quite versatile; however, they are operated in selected mode by controlling the pulses created by the waveform shaper.